1. Field of the Invention
The present invention relates generally to systems and methods for data storage, and more specifically to systems and methods for directing a robotic storage system.
2. Description of Related Art
Robotic storage systems, also referred to as robotic storage libraries, have been a staple in digital mass storage for back-up and server applications. More specifically they are commonly used to archive data, i.e., store data that is not immediately needed by a host computer. When a host computer needs the data, the robot storage system acts to retrieve and provide the needed data.
Within the robotic storage system, data is archived on physical long term storage media, such as, for example, tape. When a request is received for data, the robotic storage system identifies the physical long term storage media containing the specified data and a robot transport mechanism is dispatched to retrieve the long term storage media and provide it to a data transfer interface that is capable of establishing a communication path between the storage media and the requesting host computer.
One example of a robotic storage system is a tape cartridge library. In a tape cartridge library, there are typically a plurality of shelves structured to at least temporarily store a tape cartridge. In some instances, the tape cartridges are themselves stored in movable packs that are themselves temporarily stored on shelf structures. The tape library may have more than one drive for reading data from and writing data to the tape media within the tape cartridge. Further, the library may have more than one robot operating within the library to transport tape cartridges between the storage shelves and the read/write drives.
Various manufacturers build and deploy substantially identical storage systems to different geographic locations and for different clients. In many cases, these systems emply internally moving parts, such as for example a robot and a tape cartridge. As physical movement is an inherent characteristic of such systems, the time involved in responding to a host computer request can be a factor in overall storage system performance.
Because different clients may have different needs, schemes for controlling a robotic storage system in one environment may or may not be effective in a second environment. Further still, the needs imposed by one set of host computers may vary from day to day or even hour to hour for one robotic storage system but be relatively constant for another robotic storage system.
In some cases, robotic storage system maintenance is a desired function from time to time. While clearly desirable for long term health and operation of the robotic storage system, it is, nevertheless, a task that should not interfere with host computer requests. Moreover, the desirable times for maintenance, and potentially the type of maintenance, can vary widely from one robotic storage system to another.
It is to innovations related to this subject matter that the claimed invention is generally directed.